Malik engineers provides have developed a twin screw extruder. This twin screw extruder is used for production of ldpe foam sheet used as protective packaging medium and for insulation purpose. Some hardware features of this twin screw extruder include: the extruder is supplied in screw sizes of 75 mm and 100 mm for producing foam sheet of 1000 mm width and 1500 mm width and thickness up to 8 mm. The mets [bf] series extrusion units consists of a twin screw extruder with counter rotating screws with arrangement for admission of blowing agent [usually lpg, carbon dioxide], cooling, suitable die for producing foam sheet, sizer unit, roller take off, two station winder and suitable control panels. Working of this twin screw extruder is given by: the polyethylene resin, in granular form, is loaded in the machine hopper of the twin screw extruder from where a feeder constantly drops the required quantity of material between the plasticising screws. The material is melted, as it is conveyed forward and, at appropriate point, the blowing agent is injected in the melted polymer, the compound being cooled as it travels forward and passes through static mixer the polymer, which is now mixed with gaseous product, finally exits through a tubular die and expands as a bubble, as it leaves the die. The foamed bubble is slit in line to obtain a single layer sheet and is coiled by winder. The machine is offered in screw sizes of 75 mm and 100 mm for producing foam sheet of 1000 mm width and 1500 mm width and thickness up to 8 mm.
